<?php
$score = 70;
$get = '';
$com = function ($score) {
    if ($score >= 80 and $score <= 100) {
        $GLOBALS['get'] = "优秀";
    } elseif ($score >= 60 and $score <= 80) {
        $GLOBALS['get'] = "合格";
    } elseif ($score >= 0 and $score <= 60) {
        $GLOBALS['get'] = "不合格";
    } else {
        $GLOBALS['get'] = "这是啥";
    }
    return $GLOBALS['get'];
};
function comment($fun)
{
    echo "我的成绩是" . $GLOBALS['score'] . "评价是" . $fun;
}

comment( $com( $score ) );